Module 10: Alterations Of Hematologic Function In Children (c)

Question 1

Fetal and Neonatal Hematopoiesis

-Process

Answer 1

1. Embryonic Fetal Hemoglobin has a greater affinity for oxygen than adult Hgb —
2. Normal adult Hgb %’s are established between 6-12 months

Question 2

Fetal and Neonatal Hematopoiesis

-Leukocyte and PLT counts

Answer 2

1. Lymphocyte counts — higher at birth than adult levels and continue to rise for first year of life then taper down to adult levels
2. Neutrophils, eosinophils, monocytes — High at birth and decline to adult levels right AT BIRTH
3. PLT levels are normal level at birth

Question 3

Acquired disorders of Erythrocytes

-Iron-Deficiency Anemia

Answer 3

1. Most common blood disorder of infancy and childhood — Highest incidence between 6 months - 2 yrs of age**
   —Greatest Iron stores are present 4-8 weeks after birth
   —Dietary iron is needed after 16-20 wks of age
2. Lack of iron intake or blood loss — Consider socioeconomic status d/t lack of food?
3. Clinical Manifestations — PICA, Can affect attention span in school, alertness, and learning** Tachy, weakness, irritability
4. Tx— Iron supplementation w/ Vitamin C — RESTRICT cow’s milk

Question 4

Hemolytic Disease of the Fetus and Newborn

-Info

Answer 4

1. Hemolytic disease of the fetus and newborn (Erythroblastosis fetalis)
   - Alloimmune disease
   - Maternal blood and fetal blood are antigenically incompatible
   - Maternal antibody is directed against fetal antigens

Ex: ABO incompatibility and Rh incompatibility

Question 5

Hemolytic Disease of the Fetus and Newborn

-Clinical manifestations/Test/Tx

Answer 5

1. Anemia, hyperbilirubinemia, icterus neonatorum (neonatal jaundice
   —Kernicterus —MOST CONCERNING — Bilirubin deposited in the brain and can cause death or mental retardation
2. Test— COOMBS test
3. Treatment
   - Prevention — Rh immune globulin RhoGAM to mother
   - Tx w/ phototherapy

Question 6

Inherited Disorders of Erythrocytes

-G6PD Deficiency

Answer 6

1. Glucose-6-Phosphate Dehydrongenase (G6PD) deficiency — Inherited, X-linked, recessive disorder — Risk in AA children and homozygous Males
2. G6PD is an enzyme that helps erythrocytes maintain metabolic processes despite injurious conditions like oxidative stress
3. Asymptomatic unless stressors present
   —Stressors include Fava Bean ingestion (MOST COMMON CAUSE**TEST), ASA, sulfonamides, salicylate

—Fava beans have chemicals that are HIGHLY Oxidative to RBC’s **

4. W/out G6PD oxidative stressors damage Hgb until insoluble forms of Hgb precipitate (HEINZ BODIES)***

Question 7

Inherited Disorders of Erythrocytes

-G6PD **INFO

Answer 7

1. Fava beans have chemicals that are HIGHLY Oxidative to RBC’s **
2. W/out G6PD oxidative stressors damage Hgb until insoluble forms of Hgb precipitate (HEINZ BODIES)***

Question 8

Inherited Disorders of Erythrocytes

-G6PD Clinical Manifestations

Answer 8

1. Acute hemolytic anemia**
   - Pallor
   - Icterus neonatorum
   - Dark urine - hyperbilirubinemia
   - Back pain
2. Between hemolytic episodes — NO ANEMIA — Erythrocytes survival is normal

Question 9

Inherited Disorders of Erythrocytes

-Sickle Cell Disease

Answer 9

1. Presence of hemoglobin S — Mutation causes VALINE to be replaced by GLUTAMIC ACID — Autosomal Recessive
2. Sickle cell trait — Child inherits HB S from one parents and normal Hgb from other — Rarely has Sx’s

Question 10

Inherited Disorders of Erythrocytes

-What Causes Sickling in Sickle Cell?

Answer 10

1. Decreased O2 tension of the blood — Hypoxemia
2. Increased hydrogen ion concentration — Decreased pH
3. Increased plasma osmolality, decreased plasma volume, Low temperature

This causes
-Polymerization — The erythrocytes containing Hb S stiffens, changing from a flexible, beneficial cell to an inflexible on that starves and damages tissues

Question 11

Inherited Disorders of Erythrocytes

-Sickle Cell disease Manifestations

Answer 11

1. Vasoocclusive Crisis (Thrombotic Crisis) — MOST SERIOUS**
   —Sickling is in microcirculation, Extremely painful, and SYMMETRIC
   —Hands and feet exhibit painful swelling (Hand-foot syndrome)
2. Aplastic Crisis — Transient cessation in RBC production as result of viral infection
3. Sequestration crisis —Large amounts of blood pool in the liver and spleen — can cause CV collapse — Splenectomy may be needed

Question 12

Inherited Disorders of Erythrocytes

-Hyperhemolytic Crisis

Answer 12

1. In the presence of Sickle cell AND G6PD deficiency, hyperhemolytic crisis can occur
   —Rate of RBC destruction is accelerated

Question 13

Inherited Disorders of Erythrocytes

-Acute Chest syndrome

Answer 13

1. Sickles RBC’s attach to endothelium of injured, under-ventilated and inflamed lung and fail to be Re-oxygenated
   —Can cause lung infection — Acute chest is cause of death in 25% of people w/ Sickle Cell Disease

Question 14

Inherited Disorders of Erythrocytes

-Sickle cell- Hb C Disease

Answer 14

1. Child will inherit Hb S from one parent and Hb C from other — MILDER than sickle cell anemia

Question 15

Inherited Disorders of Erythrocytes

-Clinical Manifestation of Sickle Cell Dz

Answer 15

1. Infection is MOST COMMON cause of DEATH
2. Glomerular Dz — Hyposthenuria — Inability of the tubules of the kidneys to concentrate urine — Bed wetting — Proteinuria
3. Gallstones & Cholecystitis

Question 16

Inherited Hemorrhagic Diseases

-Hemophilias

Answer 16

1. Hemophilia A — Classic — X-linked recessive mostly affecting MALES — Factor VIII deficiency
2. Hemophilia B — Christmas Disease — X-linked Recessive — Factor IX deficiency
3. Hemophilia C — Autosomal Recessive — Equal incidence in both males and females — Factor XI deficiency

Clinical Manifestations

• Hematoma formations
• Persistent bleeding from relatively minor lacerations

Question 17

Inherited Hemorrhagic Diseases

-von Willebrand Disease

Answer 17

1. Deficiency or dysfunction in von Willebrand Factor
2. Factor VIII activity is decreased
3. Autosomal DOMINANT disease — Only one copy of DZ is needed to express the disease

Question 18

Antibody-Mediated Hemorrhagic Diseases

-Autoimmune neonatal thrombocytopenia

Answer 18

1. Immunologic destruction of PLTs by antibodies — IgG
2. Mother with ITP passes abnormal IgG to infant causing transient thrombocytopenia — As maternal antibody count drops, ITP improves

Question 19

Antibody-Mediated Hemorrhagic Diseases

-Neonatal alloimmune thrombocytopenia Purpura

Answer 19

1. Maternal immunization against fetal paternally derived platelet specific antigens — Antibodies against PLT’s*
2. PLT transfusion ASAP to prevent ICH, renal and GI hemorrhages

Question 20

Antibody-Mediated Hemorrhagic Diseases

-Autoimmune vascular Purpura

Answer 20

1. Allergic Purpura — Typically occurs around 5 yrs old
2. Antibody-Mediated injury of blood vessel walls, typically arterioles and capillaries

Manifestations
-Fever, anorexia, abdominal pain (bowel hemorrhage)